LDU special disassembly tools

[asavage]

I recently discovered the Blue Drops of Death on my LDU's speed sensor, so I removed it, cleaned it, replaced the rotor bearings "just because", reassembled it, and modified the coolant manifold to bypass liquid rotor cooling.

Along the way I had to fabricate three different fixtures to remove the rotor without beating or prying things. Two of these would apply to anybody disassembling any LDU; the third would possibly be most applicable to those who, like me, didn't have a need to disassemble (split) the gearcase) and want to remove the rotor without pressing it out from the gearcase side of the assembly.

The coolant manifold comes off without fuss:

• Remove the coolant feed hose fitting (put a bucket under to catch the fluid). Don't remove the hose from the fitting;
• Remove the flyover tube bracket (up on top, about 4" from the rotor end cap);
• Unbolt the tube's flange and push up the flyover tube; it's sealed with an o-ring;
• Remove the speed sensor
• Remove six 10mm-head bolts, and use a very light pry on the open area between the bottom and middle of the coolant manifold, and the RTV releases, and you've got blue coolant on your shoes -- if you didn't put a bucket down.

But, how do you remove the Reluctor Wheel? It's pressed on to a 34.5mm shaft (how I know that . . . later will be revealed). You can't use a jaw puller.

I bought a pair of GR8 1/4-20 bolts (~ 12.9, 6mm), ground the heads to fit through the reluctor wheel's slots, and then used a standard puller setup:






OK, that was simple enough, but then the real enemy rears its head: RTV!
How does one remove the rotor end cap?
(shown here with reluctor wheel still installed)


It's ~12" dia. and slathered in high-adhesion RTV . . . and it doesn't even need to seal anything but rainwater and dust

It seems that others have either beat on it . . .


. . . pryed on it . . .


. . . pressed it out with the rotor (from the gearcase side) . . .

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[asavage]

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. . . or like Johan, used hydraulics:


These methods (except pressing on the rotor from the gearcase side) place an asymmetrical load on the end cap casting, and Tesla provided precious little exposed metal on that tiny ledge:

I made a puller adapter from 3/4" steel, and bolted it to the rotor end cap where the coolant manifold mounts in the center.

Tesla doesn't fully tap those holes, and their assembly process gets excess RTV in the holes, making it impossible to use the entire hole unless they're re-prepped. I ran a M6x1.0 bottoming tap down these four holes a few times, clearing out the RTV and chips between runs, then made a paper doll template:


I transferred the template to the chunk of 3/4" steel and drilled clearance holes for M6 bolts:


I cut a big hole in the center, to clear my pusher bolt. It didn't need to be that large, I just had an old cheap hole saw that I wanted to used up and toss in recycling:

Use good M6 bolts here; shown are 12.9 .

That's a hardened flat washer protecting the rotor shaft end:


This applied more evenly-distributed force, and the cap came off with no fuss.


I much prefer the no-beating, no-prying methods of disassembly, when working with parts that you can't buy easily.

 

[asavage]

LDU rotor removal without pressing it out from the gearcase side.

I was fortunate in that I removed my car from service immediately upon discovering the Blue Drops of Death on the speed sensor, and I pulled the LDU out about three weeks later. I found significant corrosion to the outer end of the rotor and stator, but no liquid at the gearcase end of the rotor, and the "tunnel" where the HV phase wires connect the stator to the inverter was dry. I pulled the inverter cover and it too was dry. I decided that there was no reason to split the gearcase (with all the issues that that entails: temperature sensor connnector disassembly, etc.) and to clean/refurbish only the motor side of the LDU.

That meant removing the rotor by pulling on it, which is difficult if the rotor outer bearing doesn't provide enough friction. Put another way: if you pull on the rotor via the bearing, and the bearing comes off the rotor's shaft instead of the rotor's splined end releasing, how do you apply more pulling force?

There isn't any ledge machined on the rotor to provide purchase for a jaw puller.

The solution that worked for me -- barely -- was a bridge fixture for a puller, and a custom machined split shaft collar to seat where the reluctor wheel normally mounts. And backing up that split shaft collar: a large, quality C-clamp providing even more clamping force to that collar.

The 3/4" x 4" (19mm x 100mm) hot-rolled flatbar ($75 for 41" (~1040mm) that I began with . . .


. . . cut (!) into bridge pieces. I did not own a bandsaw last week, but I decided that this many cuts in 3/4 plate meant I needed to up my tool collection. A cheap Taiwanese saw (sold under various brand names: Central Machinery, Jet, Shop Fox, etc.) purchased used. It has seen a lot of use, but after a minimum of cleaning and alignment, did the job without fuss. Took quite some time, though.


I had to square up the ends on the mill/drill, as the bandsaw's accuracy is . . . marginal. Good enough for a rough-cut, though. Then, tap drill, then clearance drill, then tap the bridge pieces:


An . . . unusual setup for me:


A bit of very perpendicular tapping . . .


This fit "as designed":



Now, about that shaft collar . . . I couldn't locate an off-the-shelf shaft collar for 34.5mm . . . so I bought a 30mm one, in steel, and used a boring head to take it out to 34.5mm:


This fit very well:



It didn't, however, fit so snugly that I could apply enough force to pull the rotor. It -- and the bearing behind it -- slipped still. I used a honkin' C-clamp to augment the collar:

(the C-clamp doesn't really fit well, but . . . got the job done. I'd've liked to take the time to adapt this better, but since it worked as-is . . . )

That additional clamp made the difference, and the rotor came out . . . leaving the rotor's inside bearing in the case! You won't see pictures of that on the internet; that bearing "always" comes off with the rotor.


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[asavage]

(con't from prev. msg.)




I have two slide hammers with reversible 3-jaw adapters, and even with the bigger 10lb one, it was pretty marginal pulling that bearing using the slide hammer. I'm thinking either a larger slide hammer, or another use for the bridge fixture might be needed if it was mounted any harder.

You can just see the green bearing mount compound under the bearing in that last pic.

 

[dfergenson]

asavage, this is fantastic! Can you post diagrams so I can try to produce a set? I’m going to need to do this sooner or later.

I’m going to post something similar on your other thread.

-Davio

 

[gpearce]

I have been watching this forum for a few years now and I’m really torn between trying to get one cheap enough to justify the shipping to Canada and just converting my 2012 V6 to electric by stuffing a model 3 drive train in it. All the new EVs have way more tech and bells and whistles than I’m remotely interested in. We’ll ignore the cost of buying one on my pension.
Buying one and shipping should be cheaper but trying to keep it going when you’re about 2000 miles away from anyone who can help you with it is tough. Mechanicals and basic electric I shouldn’t have a problem but electronics could be.
At least I see enough information on here to think I can keep it going but I have to get a fairly good one cheap enough after shipping. That’s what I suspect is going to be impossible for at least a few years yet. $ exchange rates don’t help either.
Maybe someday.

 

[asavage]

There isn't just one or two weak areas with the RAV4 EV.

On the LDU, once the original steel ball bearings on the rotor are replaced, and you get rid of the rotor liquid cooling, these things are stout units. The original axle seals always leak, but my replacements at 70k are dry (I replaced them anyway). But the rotor seal leak issue makes them a very risky used EV, unless you've definitely got a dry one and can do the coolant delete mod without dropping the LDU out. If you have to pay someone to dry/clean/reseal, it's too much of an investment for many folks to take on, and still too few shops that do a good job of it (lots of profiteers and horror stories).

• The OBC fuse issue: changing them once isn't proof against a future failure.
• The battery contactors issue. Fix once, done.
• The Denso GEN1 heater issue, taking out the fuse in the DC-DC Converter issue. Fix once, done.

I expect the navigation system HDDs to start crapping out soon en masse. I haven't found anybody's write-up on how to clone a working one to an SSD yet . . .

Still, if mine were totaled tomorrow, I'd go buy another. For my needs, it works well (except the lack of DCFC via CCS, which I am working on, and Ricky has working already). I also appreciate that it can't phone home and make my insurance rates go up. Until data privacy in automobiles is fixed, I'm quite reluctant to buy anything newer, on principle.

 

[asavage]

Can you post diagrams so I can try to produce a set? I’m going to need to do this sooner or later.

Well, this is just straightforward fabrication.

For the rotor cap puller adapter, reverse-engineering my paper doll template into dimensions that are accurate enough to share with confidence would take a couple of hours, whereas making your own paper doll and using a transfer punch (or whatever you have) would be minutes. It's a chunk of 3/4" steel plate about 6" square (piece shown below was later cut closer to 6" square; that weird chunk was some rem I found for cheap that day), with four ~17/64" clearance holes for the M6 bolts, and some large-ish hole in the center large enough to accommodate whatever pusher you'll use.

I originally was going to use a G8 3/4" bolt:




But it was too hard to manipulate wrenches in that restrained space between the M6 bolts, and I quickly gave up and used an off-the-shelf puller set I had around instead.

For the rotor puller bridge adapter, that was 3/4" x 4" steel flatbar I bought as a remnant (still was pretty expensive, IMO), bandsawed it (with my new-to-me bandsaw) to 11-1/4" (left it oversize by design), then cut two "legs" of the same material, 5-1/8" long. Welding them to each other would make more sense than bolting, except that I wanted it to be able to be broken down, for storage and for shipping, in case I needed to loan it out.

The rotor puller setup won't work without the split set collar, and that pretty much requires machining. I own a boring head but not a lathe, so I used the tool I had.

The reluctor wheel, that was just hardware store bolts of sufficient hardness to withstand a moderate pull, and a bench grinder, nothing fancy there, plus a std "bolt grip" puller (steering wheel puller, harmonic balancer puller, etc.) but IDK how else you'd pull this delicate wheel without doing damage. I assume others pull it off by using the rotor cap as a backstop or something. The way I did it was a lot better than that.

 

[miimura]

I have been watching this forum for a few years now and I’m really torn between trying to get one cheap enough to justify the shipping to Canada and just converting my 2012 V6 to electric by stuffing a model 3 drive train in it. All the new EVs have way more tech and bells and whistles than I’m remotely interested in. We’ll ignore the cost of buying one on my pension.
Buying one and shipping should be cheaper but trying to keep it going when you’re about 2000 miles away from anyone who can help you with it is tough. Mechanicals and basic electric I shouldn’t have a problem but electronics could be.
At least I see enough information on here to think I can keep it going but I have to get a fairly good one cheap enough after shipping. That’s what I suspect is going to be impossible for at least a few years yet. $ exchange rates don’t help either.
Maybe someday.

There are people in Quebec and people in BC that work on these cars.

 

[gpearce]

There are people in Quebec and people in BC that work on these cars.

And still over 1000 miles away. But easier to talk to about issues. I know there is a few of them up here and I was contacted by a probable scammer about one. I didn’t hear back once I said I would arrange for a shop to verify the vehicle.